• 목록
• 답변
• 글쓰기
• 게시판 리스트 옵션
  • 수정
  • 삭제

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and incredible filter technology to produce the coffee we love. How exactly does it work?

In order to make espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee, but the major difference is in the pressure.

The Group Head

As the name suggests, the group head is the place you put your portafilter in when making espresso. It disperses water in the portafilter, and then regulates the pressure during the extraction. There are numerous kinds of group heads, each with its own advantages and disadvantages. Some are designed to provide stability of temperature while others are designed to handle pre-infusion. Some are designed to control the lever. Some come with a combination of both, such as the E61. This is a favorite among baristas since it provides multiple benefits in one package.

As you can see in the photo above the group head is made up of many notches in which you can put your portafilter, then twist it by hand to secure it. There is also a rubber gasket that is a part of the notches, which helps create a seal when you insert your portafilter into the machine. The notches on the head allow for a precise positioning of the portafilter which is necessary to ensure an efficient extraction.

Apart from allowing you easily insert your portafilter, the group head is responsible for maintaining a consistent temperature. It does this by circulating hot water through the brew basket, and around the portafilter, ensuring that it is always at the right temperature to extract. It is important to note that even a small difference can make the difference between a great and a excellent espresso and filter coffee machine.

The Pump

Unlike manual piston machines, that use a lever to pressurize water, rotary espresso machines rely on motorized pumps to deliver the nine atmospheric bars of pressure that are required for espresso extraction. This pressure builds up by drawing tap water from a reservoir, and pumping it through a heat exchanger prior being pushed through the ground coffee inside the group head.

Pumps are generally less expensive than piston-driven machines and tend to last longer, however both types of machines could be damaged by excessive use and inadequate cleaning. Pumps are also more complicated mechanically, which can raise the price of even the simplest models.

Certain espresso machines remove the pump completely and make use of steam pressure to make espresso. This can cause over-extraction because the boiler that makes steam also warms the water to boil. In addition these machines are often required to rebuild their pressure between cups, which takes time and energy.

Many espresso machines utilize the rotary or vibration pump, which is a vibration model that uses a vibrating disc that generates the pressure and rotating models that push hot water through the grounds under high speed. Both machines can make excellent espresso however rotary machines tend to be more stable, quieter and less likely to break down.

The Boiler

The boiler will heat the water to the ideal temperature for extraction. The steam produced is then directed to the portafilter, which holds the espresso grounds. The steam is then channeled into the cup. The steam causes enough pressure to push the grounds of coffee through. This results in a crema on the top of the espresso. This is one of the hallmarks of a good espresso.

There are three different types of espresso machines, each with different pumps and the temperature of the brew. There are different ways in which the brew could be controlled as well as the dimensions of the cup the machine is capable of making.

The first espresso machines were steam type. The earliest espresso machines were steam types. This resulted in the coffee tasting bitter and burnt. This is why Milanese makers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most common espresso machine, for beginners, is a semiautomatic with an electric pump. This is what people envision when they think of an espresso machine. With a semi-automatic espresso machine, you grind the beans and tamp them yourself but the pump provides regulated water flow and pressure. This is an excellent solution that combines human control with mechanised consistency.

The Filter

Typically, best espresso machine under 500 machines use filters to separate the grounds of coffee as they move through the hot water. The filter is also a crucial element of the temperature control system, as it prevents the machine from overheating.

A filter also improves flavor as it allows for the beans to flower for a longer period of time. This lets the beans release their nuances, and allows for a better extraction.

It is important to keep in mind that even the most efficient filter can produce a bad cup of coffee. The quality of the beans, as well as the extraction, remain crucial.

This is where the magic happens, it's the thing that makes an compact espresso machine really taste good. The grouphead (also known as the brewhead) is where you put the portafilter, the thingy used to place the grounds of your coffee into when making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight tank to produce steam, which then pushes the hot water through the grounds at high pressure. They are less expensive and easier for the owner to maintain than pumps-driven models. However, they are not as efficient in their ability to provide the ideal conditions for brewing because they operate at 1-1.5 bars of pressure. While the perfect shot requires 9-10 bar.

In recent years, compressed air-pump-driven espresso machines have been gaining popularity. They make use of an air compressor to push hot water across the ground and are more mobile than electric steam-driven espresso machines.